What are some beginner friendly openings for black that lead to open positions.
After e4 you can play e5 and enter the so called: "Open Games", 1 e5 is a friendly beginner opening (sometimes it gets played even at the GM level) but it lacks of ambition, how are you gonna beat white if you copy him but you start later than him? Luckily this first move advantage is very small at the beginner level as players are more likely to miss tactics so you can definitely Play e5 and get a nice position
Guioco Piano is a popular line in the italian game that can lead to open positions and is fun to play.

Chess Openings Resources for Beginners and Beyond...
https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond
Against 1. e4 the most forcing way to an open position is probably the Scandinavian (1. e4 d5), where White does not have a good option to close the center. The main line is 2. exd5 Qxd5 3. Nc3 Qa5, the best alternative to taking the pawn is probably a transposition to Van Geet by 2. Nc3 and still Black can open the center with dxe4. The pawn advance 2. e5 is problematic due to 2. ... c5, which makes it impossible to support the pawn with d4.
In 1. e4 e5 openings there are options for open play, but if White wants a closed position, they can get it. After 2. Nf3 Nc6 the Scotch (3. d4 exd4 4. Nxd4) always leads to an open position, but the Italian (3. Bc4) and Ruy Lopez (3. Bb5) can lead to closed positions. In the Italian White can play 4. d3 in both the Giuoco Piano (3. ... Bc5) and the Two Knights defence (3. ... Nf6) and the position remains very quiet and closed. In Ruy Lopez there are some lines that lead to open positions, but the lines are quite long. The main line of the Berlin defence opens the position, but Black gives up the right to castle (1. e4 e5 2. Nf3 Nc6, 3. Bb5 Nf6 4. 0-0 Nxe4 5. d4 Nd6 6. Bxc6 dxc6 7. dxe5 Nf5 8. Qxd8 Kxd8) and the queens are exchanged so the line is not in everyone's taste. The other way for an open position is the Marshall Attack, but the line is even longer (the fireworks start on move eight). Again if White plays some d3-setup, the position can be rather closed.
Against 1. d4 the most straightforward way to an open center is Queen's Gambit Accepted (1. d4 d5 2. c4 dxc4), provided White plays 2. c4. The problem is that White gets a strong pawn center, but if you're OK with that, then you should be fine. The problem is that the other popular d4-based opening is the London system, where White does not play c4 and the whole idea is to keep the position closed. One way of trying to open such a position is to play 2. ... c5 and then capture on d4. Also Benoni-type ideas work against the London (Black plays 1. ... Nf6 2. ... c5), but the problem is that if White plays the proper Benoni (3. d5) the position becomes rather closed.

After e4 you can play e5 and enter the so called: "Open Games", 1 e5 is a friendly beginner opening (sometimes it gets played even at the GM level) but it lacks of ambition, how are you gonna beat white if you copy him but you start later than him?

Btw you play e5 ( or c5) to prevent white from playing 2.d4, getting a full center. You're not playing 1...e5 to copy white..

After e4 you can play e5 and enter the so called: "Open Games", 1 e5 is a friendly beginner opening (sometimes it gets played even at the GM level) but it lacks of ambition, how are you gonna beat white if you copy him but you start later than him?
So, then, after the OP reaches 1600-1800 he can move away from 1...e5 to something else. But in the meantime....

After e4 you can play e5 and enter the so called: "Open Games", 1 e5 is a friendly beginner opening (sometimes it gets played even at the GM level) but it lacks of ambition, how are you gonna beat white if you copy him but you start later than him?
So, then, after the OP reaches 1600-1800 he can move away from 1...e5 to something else. But in the meantime....
ehm... I was quoting ConfusedGhoul ( who is a little confused ).
It's true that 1...e5 can and should be played by beginners, but is a high level ("top tier", whatever you want to call it) opening... extremely common at super gm level, with an immense amount of theory and room for improvement.